Currently, there are various mechanisms which offer varying degrees of support and control of the foot. Insoles such as arch supports, custom footbed and orthotics have been known for years. Such insoles are designed to alleviate foot problems, provide comfort and give better performance. The insole not only supports the foot but the whole body aligning joints in the foot, knee, hip and back while molding to the exact contours of the arch. Some inserts are off-the-shelf and those cannot be adjusted to an individual user's foot, others are semi-custom formed taking a partial mold or only adjusting to the foot slightly.
Most insoles attempt to support the foot but because of the various foot arch heights, cannot offer a lot of arch support. Most insoles are made with a lower arch height because if the arch were too high, many individuals would find it uncomfortable. A high arch can create excessive pressure under the arch yielding a very uncomfortable fit. Often the excessive arch height can cause foot cramping or injury. Most over-the-counter insoles have very low heel cups and medial and lateral flanges that do not adequately secure the heel or control the foot. They also offer little or no arch support. Over the counter insoles are made via injection molding, skive molding or compression molding processes. Some these insoles are flat, others have little shape. Still others offer deep heel cups with little or no arch support.
Most semi-custom insoles offer a one-time fit and cannot be adjusted. A few semi-custom and custom insoles offer more arch support but are difficult to manufacture and need adjustments by experienced lab technicians who use a grinder to sand away excess material.
Most semi-custom and over-the-counter insoles are designed for the pronated foot. A pronated foot is one where the ankle rolls inward. Insoles slow down or prevent some pronation from taking effect. A small amount of pronation is considered normal and is needed for shock absorption. Locking up the pronatory effect of the foot with excess arch support or wedging under the heel or forefoot by an untrained user or technician can make the body susceptible to injury.
Other insoles are available with various arch heights or different stiffness but it is up to the user or technician to decide which arch height is best. This provides a potential for harm if either too much or too little support is chosen. This could injure or further injure the foot or body.
Some insoles use compression molding. However, present compression molding methods mold multi-density material of different thickness and material in a one step compression molding process. The drawback for this process is during the compression molding process the softer material is compressed to a very thin state making it useless other than for cosmetic purposes. The one-step compression molding process makes all the multiple layers feel like the same density.
The insoles, which are available, use compression molding. However, present compression molding methods mold multi-density material of different thickness and material in a one step compression molding process. The drawback for this process is compression of the softer material to a very thin state making it useless other than for color. The one-step compression molding process makes all the multi-layers feel like the same material.
Thus, there is a need for an insole that may be adjusted for multiple arch heights. There is a further need for an insole that may be adjusted easily without any error. There is yet another need for an insole that may be used with a normal foot, a pronated foot, a flat foot and a high-supinated foot. There is also a need for an insole that allows flexible heel and forefoot support. There is also a need for a method to manufacture other types of adjustable inserts for other orthopedic applications.